Application of EST-SSRs to Distinctness Test of New Varieties

In this study,in order to investigate the feasibility of selection of identification varieties for DUS tests of winter wheat cultivars,21 pairs of EST-SSR markers were used to analyze the genetic diversity among 45 winter wheat cultivars released in Huanghuanhai region.Among the 23 newly released cultivars,61 loci were detected.The number of alleles per locus ranged from 2-8,with an average of 2.90.Nei's allelic diversity per locus varied between 0.08 and 0.79,averaging 0.38.The pair-wise genetic distance varied from 0.12 to 0.69 with a mean value of 0.40.With regard to the parents of the new varieties,63 loci were detected among 23 cultivars.The number of alleles per locus ranged from 2-7,with an average of 3.00.Nei's allelic diversity per locus varied between 0.08 and 0.79,averaging 0.43.The pair-wise genetic distance varied from 0.09 to 0.81 with a mean value of 0.46.The newly developed cultivars had a lower genetic diversity level than their parents,highlighting the need to broaden the genetic base of winter wheat breeding materials in Huanghuaihai region.Six major groups of cultivars were identified by cluster analysis.All 45 wheat cultivars could be distinguished.However,not all of the candidate varieties were grouped together with their corresponding similar varieties,with some similar varieties being clustered in different groups from relevant candidate varieties.The results showed that it was feasible to use the EST-SSR markers to help with selecting similar varieties in DUS testing.